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ROV EXPLORATION OF SANTORINI CALDERA, GREECE
Nomikou P.¹*, Croff Bell K.², Bejelou K.¹, Parks M.³, Antoniou V.¹
1 National and Kapodistrian University of Athens, 15784 Zographou, Athens, Greece 2 Graduate School of Oceanography, University of Rhode Island, Narragansett Bay Campus, USA
3 University of Oxford, UK
10ο Πανελλήνιο υμπόςιο Ωκεανογραφίασ & Αλιείασ7-11 Μαϊου 2012, Αθήνα
These three main volcanic centers
and all the smaller volcanic cones
northeast of Kolumbo, are
aligned along the NE-SW trending
Santorini-Kolumbovolcano-tectonic
line
(Nomikou et al., 2012
GLOPLACH)
Sigurdsson et al., 2006
Hydrothermal vents occur in both the
North and South Basin of the caldera.
They form a vent field in the NE part
of the North Basin that is 200 by 300m
in extent. The vents form hundreds of
1 to 4m diameter mounds of
yellowish bacterial mat that are up to
1m high. Temperatures in the mound
are around 15 to 17 C or about 5 C
above ambient temperature. The North
Basin hydrothermal vent field is
located in line with the normal fault
system of the Kolumbo rift, and also
near the margin of a shallow intrusion
that occurs within the sediments of the
North Basin. Similar vent mounds
occur in the South Basin, where most
of the low temperature vents are seeps
along a ridge separating the West and
South Basins and on the submarine
flanks of the Kameni volcanic islands.
500m depth
The caldera rim lies at about 150 m depth forming a submarine circular cliff of 350 m.The crater walls display a scalloped morphology that is visible by undulating contour lines.
The topographic difference is apparently created by the collapse of a relevant volcanic cone
Swath Bathymetric Map of Kolumbo Volcano
Nomikou et al., (2012-in review)
Carey et al., 2011, Oceanography
Οι υδροθερμικϋσ
καμινϊδεσ παρουςιϊζουν
υψηλό πορώδεσ, με
ϋναν κεντρικό αγωγό που
δομεύται από ςουλφύδια και θειώκϊ ϊλατα και βοηθϊ τη
ροό των ρευςτών προσ
τα ϋξω.
Parks et al., 2012, Nature (in review)
Our soil gas surveys detected an apparent increase in CO2
emissions between July 2011 and September 2011. CO2
effluxes now exceed 12 kg m-2 day-1, with a total flux of 39 tonnes of CO2 per day (Parks et al, 2012)
The source has an effective volume of 1−2×107
m3 for the full year of 2011, and is centredslightly to the north of Nea Kameni at a depth of 4-7 kilometres.
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